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Women's Health

Miscarriage

Miscarriage is the spontaneous loss of a pregnancy before 24 weeks; this chapter focuses on early pregnancy loss, where ultrasound, clinical stability and the amount of tissue passed determine diagnosis, urgency and management.

In a nutshell

For early-pregnancy bleeding, first assess stability and exclude ectopic pregnancy. Once a miscarriage is confirmed, expectant, medical and surgical management are alternatives within safety boundaries. Know the NICE ultrasound safeguards, the 2023 diagnosis-specific medical regimens, 3-week pregnancy-test follow-up and June 2026 anti-D update.

Classic presentation

Vaginal bleeding with lower abdominal cramping in early pregnancy, with or without passage of tissue; missed miscarriage may be asymptomatic and ectopic pregnancy must remain in the differential until location is secure.

Key points

  • Unstable, septic, severely painful or heavily bleeding: emergency gynaecology assessment; do not wait for serial hCG.
  • Use transvaginal ultrasound for location and viability. Do not diagnose miscarriage from the last menstrual period alone or from one borderline scan.
  • If an empty uterus is seen without a previous confirmed intrauterine pregnancy, manage as possible pregnancy of unknown location until follow-up is complete.
  • Threatened miscarriage: confirmed intrauterine pregnancy with fetal heartbeat and bleeding; offer vaginal micronised progesterone only when there is also a previous miscarriage (see BNF/local protocol for medicines).
  • Expectant management is first line for 7 to 14 days when clinically safe and acceptable; reassess sooner if bleeding/pain does not start or persists/increases.
  • Missed miscarriage: mifepristone followed 48 hours later by misoprostol; incomplete miscarriage: misoprostol alone, with diagnosis-specific doses (see BNF/local protocol for medicines).
  • After expectant or medical management, use a urine pregnancy test at 3 weeks; a positive test needs review for retained, molar or ectopic pregnancy.
  • Current anti-D rule: none up to and including 11+6 weeks; at 12+0 to 12+6 weeks offer at least 250 IU to RhD-negative people having medical or surgical management, and consider it for threatened miscarriage with heavy/recurrent bleeding (see BNF/local protocol for medicines).

First-line investigation

Immediate clinical assessment followed by appropriately performed transvaginal ultrasound; use serial hCG only when pregnancy location remains unknown.

Management

Stabilise and exclude ectopic pregnancy

  • Emergency assessment for instability, heavy bleeding, severe pain, sepsis or uncertain pregnancy location; resuscitation and senior gynaecology escalation take priority.1,3

Confirm location and viability

  • Use transvaginal ultrasound and repeat an uncertain scan according to NICE safeguards; do not use LMP alone or label an empty uterus as complete miscarriage without appropriate follow-up.2

Treat threatened miscarriage selectively

  • With scan-confirmed intrauterine pregnancy, bleeding and previous miscarriage, offer vaginal micronised progesterone; continue to 16 completed weeks if a fetal heartbeat is confirmed (see BNF/local protocol for medicines).4,7

Choose expectant, medical or surgical management

  • Expectant management is first line for 7 to 14 days when safe and acceptable; offer medical or surgical alternatives when needed or preferred, with clear pain, bleeding and emergency advice.4

Use the correct medical regimen and follow-up

  • Missed miscarriage uses mifepristone then misoprostol; incomplete miscarriage uses misoprostol alone. Check symptoms and provide a 3-week urine pregnancy-test pathway (see BNF/local protocol for medicines).4,8,9

Apply anti-D and support recovery

  • Apply the June 2026 anti-D rule, review a positive 3-week pregnancy test, give 24-hour safety-netting and offer emotional support after pregnancy loss (see BNF/local protocol for medicines).5,3,6

Exam traps

  • A positive pregnancy test plus bleeding is not automatically miscarriage; ectopic pregnancy must be excluded.
  • A single scan with uncertain viability should not be overcalled; follow NICE repeat-scan safeguards and do not use LMP alone.
  • Mifepristone is used for missed miscarriage, not incomplete miscarriage; the medical regimens are not interchangeable (see BNF/local protocol for medicines).
  • A positive urine pregnancy test 3 weeks after expectant or medical management needs clinical review, not simple reassurance.
  • Anti-D is not routinely offered up to and including 11+6 weeks under the June 2026 NICE recommendation, including for medical or surgical management.
  • Progesterone is not a universal treatment for early-pregnancy bleeding: the NICE indication requires a scan-confirmed intrauterine pregnancy, current bleeding and previous miscarriage (see BNF/local protocol for medicines).

Illustrations

Spectrum of miscarriage subtypesDiagram showing threatened, inevitable, incomplete, complete and missed miscarriage as clinical states defined by viability, cervical findings and whether pregnancy tissue has passed; avoid implying that every case progresses through every subtype.PassFinals · original
Ultrasound of an anembryonic pregnancyTransvaginal ultrasound showing an empty gestational sac in early pregnancy loss, with a reminder that an uncertain scan must be repeated according to NICE safeguards before diagnosing miscarriage.Mikael Häggström, Wikimedia Commons · CC0
Management pathway for miscarriageFlowchart from immediate stability and pregnancy-location assessment to expectant, medical or surgical management, including repeat-scan safeguards, follow-up and the current anti-D pathway.PassFinals · original

Key sources

  1. NICE NG126: Symptoms and signs of ectopic pregnancy and initial assessment (NG126 recommendations 1.1 to 1.4)Published 17 Apr 2019 | Updated 17 Jun 2026
  2. NICE NG126: Diagnosis of viable intrauterine pregnancy and tubal ectopic pregnancy (NG126 recommendations 1.5 to 1.8)Published 17 Apr 2019 | Updated 17 Jun 2026
  3. NHS: Miscarriage (NHS symptoms, diagnosis, treatment and support information)Updated 31 Mar 2026
  4. NICE NG126: Management of miscarriage (NG126 recommendations 1.9 to 1.12)Published 17 Apr 2019 | Updated 17 Jun 2026
  5. NICE NG126: Anti-D immunoglobulin prophylaxis (NG126 recommendations 1.18, updated June 2026)Published 17 Apr 2019 | Updated 17 Jun 2026
  6. BNF: Anti-D immunoglobulin (BNF immunoglobulin monograph)
  7. BNF: Progesterone (BNF progestogen monograph for safe prescribing and administration)
  8. BNF: Mifepristone (BNF antiprogestogen monograph for safe prescribing and administration)
  9. BNF: Misoprostol (BNF prostaglandin analogue monograph for safe prescribing and administration)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.